Slug casting machine



March 24, 1936. Q p. K|NGSBURY 2,035,076

SLUG CASTING MACHINE Filed Aug. 28, 1934 5 Sheets-Sheet 2 IN VENTOR Mai-ch 24, I936. e. P. KINGSBURY 2,035,076

SLUG CASTING MACHINE Filed Aug. 28, 1934 5 Sheets-Sheet- 3 March 24, 1936 p KlNGSBURY I 2,035,076

SLUG CASTING MACHINE Filed Aug. 28, 1934 5 Sheets- 511991. 4

INVENTOR.

G. P. KINGSBURY 2,035,07

SLUG CASTING MACHINE Filed Aug. 28, 1934 I 5 Sheets-Sheet 5 lA /VENTOR BY w a P7 2 5 Patented Mar. 24, 1936 FFIQE SLUG CASTING MACHINE George P. Kingsbury, Hollis, N. Y., assignor to Mergenthaler Linotype Company, a corporation of New York Application August 28,

18 Claims.

This invention relates to slug casting machines, such as machines of the general organization represented in United States Letters Patent to O. Mergenthaler, No. 435,532, wherein circulating matrices and expansible spacebands are composed in line by th manipulation of a keyboard, the composed line transferred to a slotted mold for the casting of a type bar or slug, and the matrices and spacebands thereafter separated and returned by a distributing mechanism to the magazines from which they started.

In these machines, when the composed line is presented to the mold, it is positioned between a pair of clamping jaws which have previously been set to receive it, and while so positioned, the line is justified by the expansion of the spacebands which are driven up through the line by a so-called justification bar operated prior to the casting operation. Ordinarily, the righthand jaw is relatively fixed (having only a limited movement to operate the customary pump stop), whereas the left-hand jaw is adjustable to different positions to accord with the length of the mold slot orwith the length of the composed line in its justified condition. In casting under such conditions (which are the most common conditions), it is obvious that the number of matrices and spacebands composed must be sufficient to fill out the line completely (except of course for the limited space allowed for justification) and hence when it is desired to cast slugs with blank spaces at the ends for indenting or centering, it is necessary to employ blanks or quads for that purpose, involving considerable annoyance and delay.

It is now common practice to equip the machines with quadding and centering devices which adapt them to handle not only lines of full length as ordinarily, but in addition lines of less than full length (regardless of their actual length), so that the latter lines may be composed without blanks or quads and merely with the matrices necessary for the printed matter. While various schemes of this sort have been proposed, the devices disclosed in U. S. Patents Nos. 1,949,302 and 1,971,400 to Frank C. Frolander offer many improvements upon prior arrangements in the way of greater simplicity, better eificiency, and more extended scope of operation, and the present invention is directed to still further improvements to the same general end.

As one feature of this invention, one or both of the jaws are movable from line receiving position into contact with the line or alternatively to a definite position out of contact with the line and locked in the moved position, so that, whether quadding with either jaw or centering, different type lines may be cast of varying lengths or of a definite and uniform length, as desired.-

As another feature of the invention, the rod 1934, Serial No. 741,767

connected to the jaws is raised and lowered by a low-pitch screw operated through a train of connections by a cam on the main cam shaft of the machine. With this arrangement, it is impossible for the rod to move except when actuated by the screw and, hence, it is automatically locked in whatever position it may be when the screw ceases to function, it (the rod) in turn looking the jaws in the position to which they have been moved.

In order that the jaws may be arrested in different positions, a pair of cams, one for quadding and the other for centering, are provided to en.- gage a lug or stop on the rod, the cams being selectable as required and rotatable to bring different portions into position to engage the stop for arresting the rod at different heights.

A friction clutch is arranged in the train of connections for operating the screw so that whenever the rod is arrested by the stop cams, the clutch will disengage or slip to permit the connections between it and the driving cam to continue their operation without rotating the screw. When the cams are not set to arrest the jaw short of line contacting position, the engagement of the jaws with the line causes the clutch to slip and the jaws become locked in line contacting position.

These and other features of the invention will be fully set forth in the detailed description to follow.

Referring to the drawings:

Fig. 1 is a front elevation of a portion of a slug casting machine equipped with the present improvements;

Fig. 2 is an elevation of the parts shown in Fig. 1, looking from the left in that figure;

Fig. 3 is a front elevation of the vertically movable rod, and the associated parts, for moving the jaws to and fro, certain parts being shown in section and others broken away;

Fig. 4 is a view taken on the line 44 of Fig. 2, looking down from above;

Fig. 5 is a view taken on the line 5-5 of Fig. 3, looking down from above;

Fig. 6 is an elevation of the cam selecting and adjusting mechanism, partly broken away; and

Fig. '7 is a plan view of a printing form, illustrat-ing the different kinds of slugs which may be cast.

The matrices andexpansible space bands are composed in line in the assembler A under the restraining influence of a line resistant (not shown) which can be set for lines of diiferent length, all in the usual way. After the line has been composed, the assembler is raised to position the line between the fingers of the line delivery carriage B, which thereupon moves to the left (and in doing so inaugurates the operation of the machine) and transfers the composed line through the intermediate channel B into the vertically movable transporter or first elevator C slidably mounted in the vise frame D. Upon receiving the line, the first elevator immediately descends to position it between the left-hand jaw E and the right-hand jaw F and in front of the slotted mold G, which latter then advances from the rear and into contact with the line and the two clamping jaws for the slug casting operation, the line, prior to casting, being alined and justified in the usual way when the machine is being operated under the usual conditions. After the slug has been cast, the mold is carried from its horizontal casting position (as shown in Fig. 1) to a vertical ejecting position by a three-quarter rotation of the mold disc G the first elevator in the meantime being raised to deliver the composed line to the matrix and spaceband distributing devices and finally coming to rest in its original or line receiving position, as shown in Fig. 1.

As already stated, the Frolander patents before noted provide devices whereby the line clamping jaws may be operated automatically to cooperate with lines of less than full length so as to cast slugs with blank spaces at either end, as for quadding, or at both ends, as for centering. It should be stated perhaps that each of the jaws E and F is made long enough, when used alone for quadding, to close that part of the mold slot left exposed by a short composed line, or in the absence of a composed line, to close the mold slot completely. Except as thus modified, and as hereinafter noted, the two jaws are substantially the same as those employed in the commercial machines and they are mounted for movement in the vise frame D in the customary manner, being carried by supporting blocks E and F slidable in suitable guideways formed in the vise frame D.

The two jaws E and F are movable toward and from each other by a periodically operated part in the form of a vertically movable rod H which may be connected at its upper end to the respective jaws through the medium of two similar but oppositely disposed bell-crank levers E and F pivoted at E and F to the vise frame D, the longer arms of said levers being connected by short links E and F to the jaw supports E and F respectively, and the shorter arms of said levers being arranged for connection to the rod H. According to this arrangement, when the rod H is moved downwardly from its uppermost position (which is its normal position of rest, as shown in Fig. 1), it will move the two jaws equidistantly toward each other (assuming both to be connected to the rod) until they contact with the opposite ends of a composed line which has previously been positioned between them, and when the rod is moved upwardly for restoration to its position of rest, it will in like manner move the jaws equidistantly away from each other to return them to their original positions of maximum separation. Since the composed lines positioned between the jaws may vary in length, the actual extent of movement of the rod H will of course vary accordingly, and hence provision is made for such varied movement of the rod in its actuating connection as will presently appear.

In providing for connection and disconnection of the rod H with and from the jaws E and F, the rod carries at its upper end a grooved collar N mounted for rotation only and segmentally formed for engagement with diametrically opposed pins N (see Fig. 2), protruding inwardly from the extremities of the horizontal arms of the actuating levers E and F for the jaws E and F, respectively. When both jaws are to be connected to the rod H for centering, the collar is turned to the position which brings both of its segments into engagement with the pins N of the jaw actuating levers E and F When both jaws are to be disconnected from the rod H for regular machine operation, the collar is turned to locate the segments out of engagement with the pins N. In connecting the rod H to either of the jaws independently, the collar is moved to intermediate positions, the appropriate segment being brought into engagement with the desired pin N While the collar N could be turned directly by hand, a special control device is employed for setting the collar instantly in the required position. This device is shown in the form of a manually operable bar mounted to slide in horizontal guides O secured to: the vise frame D and disposed at right angles to the rod H. Adjacent the rod H, the bar 0 is formed with rack teeth 0 meshing with a. pinion O surrounding the rod H and rotatably mounted on a block D secured to the vise frame, the pinion 0 being seated in the block D as at D and held therein by a ring D secured to the block (see Fig. 3) The pinion O has a key 0 arranged in a vertical slot 0 formed in a sleeve 0 carried by the rod H and secured at its upper end to the rotatable collar N the key and slot connection 0 0 thus permitting the necessary relative movement between the rod H and the pinion 0 The setting of the bar 0 is effected by means of a hand crank 0" (Figs. 3 and 5) fixed to one end of a shaft 0 carrying at its opposite end a pinion O in mesh with a second set of rack teeth 0 formed on the bar 0. The shaft 0 passes through a bushing 0 formed integrally with a plate 0 secured to the vise frame D, as by the screw or bolt 0 the plate 0 being formed with a series of apertures 0 adapted to be engaged by a detent (not shown) carried by the crank arm 0 for holding the arm 0 and hence the bar 0 and collar N in different set positions. As a guide to the operator, the crank arm 0 is formed with a pointer O which cooperates with a scale on the plate 0 bearing the designations QL meaning 'quad' left CENT meaning centering, QR meaning quad right, and REG meaning regular machine operation. These designations indicate the four positions of the crank arm and are located with respect to the different apertures 0 Although differing somewhat in detail of construction; the mechanism just described is substantially the same as that shown and described in Frolander, Patent No. 1,949,302.

Coming now to the present improvements: The rod H is slidable along with the sleeve 0 in the block D the sleeve moving relatively to the pinion O as already stated. At a point below the block D the rod H is screw-threaded as at H to accommodate a threaded cap H adapted to bank against the underside of the block D as shown in Fig. 3, to limit the upward movement of the rod H, the cap H being screwed down on the threads H more or less, providing an adjustable stop for accurately determining the normal or uppermost position of the rod H. At its lower end, the rod H is fashioned to accommodate a detachable sleeve H (see Fig. 3), which is pinned to the rod and adapted tohave a sliding fit within a bearing H formed in the bracket D secured to the vise frame D, the

sleeve H being provided with a key H adapted to ride in a keyway H formed in the bearing H Just above the sleeve H the rod H is formed with screw threads H" adapted to receive an internally screw-threaded collar H carrying externally a bevel gear H, the collar being mounted between upper and lower thrust bearings H and H respectively, clamped in place by a retaining cap H (see Figs. 1 and 3) bolted to the bracket D and capable of being tightened from time to time as the parts wear or become loose. With this arrangement, the rod H is prevented from rotating by the key H but is free to move vertically, while the collar H is free to rotate but is held against vertical movement, whereby rotation of the collar in opposite directions will cause the rod H to be moved up and down. Because of the low pitch of the screw or worm drive, the rod is movable only by the rotation of the collar H and, hence, when the collar ceases to operate, the rod H and consequently the jaw or jaws connected to the rod at the time are securely locked in whatever position they may occupy.

The collar H is rotated through a train of connections operated from a cam M on the main cam shaft M of the machine (Fig. 2) and comprising a bell-crank lever H for moving a rack bar H slidable vertically in a guide H the rack bar H operating through a pinion H and a series of gear connections leading to the collar H As best shown in Fig. 4, the pinion H acts through a larger gear 1-1 to rotate another pinion H and thus step up the drive by the rack bar H Further to step up the drive, the pinion H rotates a bevel gear H which meshes with a pinion H for driving a bevel gear H at the front of the machine (see Fig. 2), the gear H in turn meshing with a pinion H arranged at right angles thereto and which drives gear H in mesh with gear H formed on the collar H (Fig. 3).

The connections just described are mounted both on the fixed frame of the machine and on the movable vise frame D and in order that the vise frame may be opened and rocked about its hinge D Without requiring any disconnection of or causing any interference with the train of connections, shafts H and H carrying gears H and H respectively, are equipped with universal joints H and H (Fig. 2) having a key and slot connection H with one another.

The bell-crank lever H is pivoted at H and its short arm H carries a roller H adapted to track on the periphery of the driving cam M, while its longer arm H is connected by a link H to the rack bar H As already stated, the rack bar H is slidable in the guide H and this guide is formed in an extension of a bracket H secured to the fixed frame of the machine by a heavy set screw or bolt H. The bracket H is also formed with three bearings H H and H in which are respectively mounted gear shafts H, H and H and in order that the bracket I-I may be adjusted so that the gears carried by the different shafts will mesh properly, two adjusting screws H and H (Figs. 2 and 4) are arranged to bear against the fixed machine frame so that by loosening one and setting up the other the bracket will be rocked horizontally about the bolt H as a pivot until adjusted and the bolt H then tightened to hold the bracket in its set position.

The shaft H (Fig. 4) has fixed to it the pinion H meshing with the rack bar H and gear H meshing with the pinion H fixed to the shaft H Loosely mounted on the opposite end of the shaft H is the bevel gear H which meshes with the pinion H fixed to the shaft H, the gear H being driven by the pinion H through a friction clutch H fixed to the shaft H and having its friction disc H pressed by a spring H against a disc H carried by the loosely mounted gear H Thus the gear H relies solely upon the friction clutch for its drive and, hence, when the rod H is arrested, the resistance offered causes the clutch to slip and allows the rack H to partake of its full stroke without rotating the gear H or any of the train of connections between it and the rod H.

The forward end of the shaft H is mounted in a bearing H (Fig. 2) secured to the fixed machine frame and the shaft is connected, as already stated, by a sliding and universal joint connection to shaft H mounted in bearings H1 and H formed in a bracket H secured to the movable vise frame D. A shaft H carrying gears H and H is disposed at right angles to the shaft H and mounted in bearings H and H formed, respectively, in brackets H and D secured to the vise frame.

There remains to be described the means whereby the jaws are arrested in a definite position out of contact with the line. This is accomplished (Fig. 3) by a stop H pinned to the rod H and provided with a set screw H adapted to engage with one or another of a pair of cams S and S the cam S being used for quadding and the cam S for centering. In order that the cams may be selected as required, they are fixed to a common shaft S which is mounted in a bushing S formed in the bracket D and passes through the machine frame and a plate S fixed thereto, and the shaft S has a knurled knob S pinned to its end for rotating it to locate different peripheral portions of a selected cam in operative position for cooperation with the set screw H A disc S (see also Fig. 6), graduated in ems and cooperating with a fixed pointer or mark S", is mounted on an extended bearing S of the plate S and held in place by a pin and groove connection S the disc S being formed with two slots S and S to receive a lug S formed on the knob S The larger cam S is employed when centering, since the rod H moves downwardly a shorter distance in moving both jaws inwardly than when moving but one jaw inwardly for quadding, and with the present arrangement, when the lug S is engaged in the deeper slot S a spring S between the machine frame and a shoulder S on the shaft S forces the shaft to the left (Fig. 3) to bring the cam S into the position shown by the full lines. To bring the other cam S into operative position, by means of the knob S the shaft may be pulled to the right (to the dotted line position) against the action of the spring S and the lug S seated in the shallow slot S to hold the parts in their shifted position. With either cam in operative position, the engagement of the lug S in one of the slots 8 or S connects the dial S to the shaft S and by rotation of the knob S the dial may be turned to the proper setting, the cams also being rotated to locate a high or low portion of the selected cam in operative position for arresting the rod'at a particular height so that the jaw or jaws will be moved inwardly the desired amount. A detent S engaging in one of a series of depressions S in the rear face of the dial may be employed to hold it in set position. At whatever height the rod H is arrested by the engagement of the set screw H with one or the other of the cams S, S the friction clutch H will be caused to slip and by virtue of the screw actuation of the rod H the latter will become locked in its arrested position until after the casting operation.

In the operation of the machine, after a composed line of matrices and spacebands has been presented to the mold, the portion M of the cam M comes into engagement with the roller H on the short arm of the bell-crank lever H and continued rotation of the cam M causes the lever H to be rocked to the dotted line position shown in Fig. 2. This rocking of the lever H moves the rack H upwardly to the dotted line position and causes the operation of the train of connections between the rack and the rod H to move the rod downwardly until it is arrested by the contact of either or both of the jaws with the line (depending upon their connection with the rod at the time) or by the engagement of the set screw H with one or the other of the cams S and S to stop the jaws in their inward movement short of line contacting position. The arresting of the rod in any event resists the action of the cam M in rocking the lever H whereupon the friction clutch H slips to allow the parts between it and the cam M to complete their full stroke under the influence of the positive actuation by the cam, the rod, and hence the jaw or jaws, being locked in the position to which moved at the time the clutch H slips since, by virtue of the screw drive, the rod H can only be moved by rotation of the collar H Justification now takes place and the line is expanded between the locked jaws. During the casting operation, the roller H rides along the high portion M of the cam M to maintain the driving connections in the position to which they have been moved. When the casting operation is completed, the roller H rides down the portion M of the cam under the influence of a tension spring H which is heavy enough to rock the lever H in the opposite direction and thus lower the rack H and through the driving connections raise the rod H to return the jaws to their initial line receiving position determined by the abutment of the collar H on the rod H with the underside of the block D the action of the spring H being limited by a stop pin H on the machine frame against which the long arm H of the bell-crank lever H banks.

Ordinarily the right-hand vise jaw, when 0ccupying its line receiving position, is adapted to actuate the so-called pump stop to prevent the injection of molten metal into the mold in the event that the line is not fully expanded between the vise jaws during justification and, therefore, some means must be provided to operate the pump stop when the right-hand jaw is moved inwardly from line receiving position. Preferably, this is accomplished by having the pump stop controlled by a movable section of the left-hand jaw as in the Frolander Patent No. 1,971,400 heretofore referred to, and wherein the details of construction and operation are fully set forth.

The printing form illustrated in Fig. '7 comprises slugs of different character which may be cast in a machine embodying the present invention. For the sake of convenience, the slugs have been divided into eight different groups, the first five of which, and those marked X, are of full em body length, and the other three of 22 em body length cast, respectively, in 30 em and 22 em length molds. The shorter slugs, when arranged as shown, leave a space Y in the printing form in which a cut or blank filler may be located.

Group 1 is composed of six slugs which, as indicated, are cast in the regular manner with the vise jaws disconnected from the rod H. The slugs of Groups 2 and 3 bear lines of characters of less than 30 ems, the slugs of the two groups illustrating, respectively right and left-hand quadding. In quadding right, as for casting the slugs of Group 2, the right-hand vise jaw alone is connected to the rod H and is moved inwardly (for an 18 em line) a definite distance of 12 ems from its line receiving position, it being arrested and locked in such inward position by the engagement of the screw H on the rod H with the cam S which has been previously set in the proper position, all as heretofore described, and the line in each instance expanded during justification to fill out the 18 em space between the vise jaws. The operation is the same when quadding left as in casting the slugs of Group 2, except that the lefthand jaw is the only one connected to the rod H. The slugs of Group 4 have lines of characters 18 ems long centralized thereon, the centralization of the line being effected by the inward movement of both jaws equal distances from their line receiving positions, both jaws having been connected to the rod H and the rod arrested in its descent by the engagement of the screw H with the cam S which has been shifted previously to operative position. Centralized lines of varying lengths are illustrated in Group 5, the slugs of this group being cast from lines composed either with expansible spacebands or with solid spacers, and the cams S and S being set in inactive position so that the jaws can move into contact with the line. This obviates the necessity of setting the cams for each successive cast.

Group 5 is separated from adjacent groups by two blank slugs X cast in the absence of a line of matrices between the vise jaws and with either one or both of the vise jaws connected to the rod H and the cams S and S set so as not to be engaged by the screw H (i. e., set in a position where the arrow S on the dial S alines with the mark S thus allowing the jaws to come together and completely close the mold slot.

Groups 6, 7 and 8 comprise slugs cast, as already stated, in a 22 em mold, in which instance the left-hand jaw is alined in the usual manner with the end of the mold slot and which position is its normal line receiving position. The righthand quadding, Group 6, and centralizing, Group 7, is accomplished in the same manner as that already described in connection with Groups 2 and 4,respectively, while the right-hand quadding of different length lines, Group 8, is accomplished by setting the cams S and S in inactive position and allowing the jaw to move into contact with the line, as in the case of the centralized lines of Group 5.

It will also be understood that lines may be quadded at the left on slugs of short body length just as in Group 3 on slugs of full body length; and by varying the line receiving position of the left-hand jaw with respect to the mold in use lines of characters may be variously located on the slug bodies, the few examples shown in Fig. 7 being only representative of the class of work which a machine embodying the present invention is capable of producing.

Having thus described my invention, what I claim is:

I. In a slug casting machine, the combination of a pair of relatively movable line clamping jaws, and mechanism for moving one of the jaws inwardly from its line receiving position to a quadding position, said mechanism including motion transmitting devices self-operative to lock the jaw in the position to which it is moved.

2. In a slug casting machine, the combination of a pair of relatively movable line clamping jaws, means for moving one of the jaws inwardly from its line receiving position, and means for arresting the jaw in its inward movement in a definite position independently of the line, said jaw moving means being self-operative to lock the jaw in its arrested position.

3. In a slug casting machine, the combination of a pair of relatively movable line clamping jaws, and mechanism for moving one of the jaws inwardly from its line receiving position into contact with the line or alternatively to a definite position independently of the line, said mechanism being self-operative to lock the jaw in either position.

4. A combination as in claim 2, wherein the jaw arresting means is adjustable to determine the extent of inward movement of the jaw.

5. A combination as in claim 1, wherein the jaw moving mechanism includes a vertically movable rod operated from the main drive shaft of the machine through a train of connections including a lo-w-pitch screw.

6. A combination as in claim 1, wherein the jaw moving mechanism includes a vertically movable rod operated from the main drive shaft of the machine through a train of connections including a low-pitch screw and means between the drive shaft and the screw to render the driving connections inoperative when the jaw reaches quadding position.

7. A combination as in claim 1, wherein the jaw moving mechanism includes a vertically movable rod operated from the main drive shaft of the machine through a train of connections including a low-pitch screw, a rack operated from a cam on the main shaft and having a full stroke imparted to it during each jaw closing operation, a pinion meshing with the rack and operating through a friction clutch in driving the screw, and spring means for returning the parts to their initial positions.

8. In a slug casting machine, the combination of a pair of line clamping jaws, one movable inwardly toward the other from line receiving position for quadding or both movable toward each other for centering, means for effecting such movement of the jaws, and means independent of the line for determining the extent of inward movement of the jaws, said means including a pair of cams, one for centering and the other for quadding, and means for selecting one cam or the other as required.

9. In a slug casting machine, the combination of a pair of line clamping jaws, one movable inwardly toward the other from line receiving position for quadding or both movable toward each other for centering, means for effecting such movement of the jaws, means independent of the line for determining the extent of inward movement of the jaws, said means including a pair of rotary cams, one for centering and the other for quadding, movable alternatively into operative position for arresting the jaws in a definite position.

10. In a slug casting machine, the combination of a pair of line clamping jaws, one movable inwardly toward the other from line receiving position for quadding or both movable toward each other for centering, means for effecting such movement of the jaws, means independent of the line for determining the extentof inward movement of the jaws, said means including a pair of rotary cams, one for centering and the other for quadding, movable alternatively into operative position for arresting the jaws in a definite position, and means for rotating the cam in operative position to vary the arrested position of the jaw or jaws.

11. A combination as in claim 9, wherein the jaw moving means includes a vertically movable rod, and wherein the cams are independently mounted on a common shaft movable lengthwise to bring one or the other into position to cooperate with a stop on said rod to arrest the latter in its movement, the shaft being rotatable to bring different portions of the selected cam into position to cooperate with the stop for arresting the rod at different heights.

12. A combination as in claim 9, wherein the jaw moving means includes a vertically movable rod, and wherein the .cams are independently mounted on a common shaft movable lengthwise to bring one or the other into position to cooperate with a stop on said rod to arrest the latter in its movement, the shaft being rotatable to bring different portions of the selected cam into position to cooperate with the stop for arresting the rod at different heights, and dial means for determining the proper adjustment of the selected cam to arrest the rod at any desired height.

13. In a slug casting machine, the combination of a pair of line clamping jaws, one movable toward the other for quadding, a screw section for effecting such quadding movement of the jaw, and means for rendering said screw section operative or inoperative as required.

14. In a slug casting machine, the combination of a pair of line clamping jaws, at least one of which is movable toward and from the other jaw, a screw, means for operatively connecting the jaw to or disconnecting it from the screw, and means for rotating the screw in opposite directions during a cycle of operation of the machine.

15. In a slug casting machine, the combination of a pair of line clamping jaws, each movable toward the other for quadding, a screw mechanism for effecting such quadding movements of the jaws, and means for rendering the screw mechanism operative upon one or the other of the jaws as required.

16. In a slug casting machine, the combination of a pair of line clamping jaws movable equidistantly toward each other for centering, a screw mechanism for effecting such movements of the jaws, and means for rendering said screw mechanism operative upon both jaws when required.

17. In a slug casting machine, the combination of a pair of line clamping jaws, each movable toward and from the other, a screw mechanism, means for operatively connecting either or both jaws to the screw mechanism as desired, and. means for rotating the screw mechanism in opposite directions during a cycle of operation of the machine.

18. A combination as set forth in claim 16, wherein a single screw is employed for effecting the movements of the jaws, and including means for selectively coupling and uncoupling the jaws to and from said screw.

GEORGE P. KINGSBURY. 

